General

[quote=ryanlli]quick question, how come viral slime doesn't multiply whenever i'm in evo or mpe[/quote]

It doesn't multiply on boss tagged monsters. Evo and MPE are boss tagged, as are places like HoH.

[quote=gerafang]I found that flame gears didn't add to DoT's passive, just damage.[/quote]

What do you mean?

As a damage multiplier for ME, it works

I never found Explosion useful after hitting 100. It doesn't give DPS, it doesn't really help mobbing much since Paralyze hits 8 and doesn't put you in as much danger as Explosion.

As the non-asinine of us have already said in the thread--don't max Explosion.

Lv. 20 Poison Mist is the prerequisite for Myst Eruption, so you need to master that. Viral Slime can be used as a damage multiplier for Myst Eruption, and Explosion doesn't really have any important uses besides being a good mobbing skill in Evo Lab

Viral Slime is actually useless in most situations 4th job and beyond

If you need a 5th DoT, uses Teleport Mastery, it's far more reliable.
Alternatively there's also Flame Gears

Mist and viral slime is used more than explosion beyond 3rd job. Leave explosion unmaxed.

You need to max viral slime AND poison mist. Viral slime is the best training skill for a 3rd job fire poison. Also, it is used later on in gollux as the slimes can take down the monsters on the bottom. They're not 100% reliable, but they work okay to at least take down one side. Viral slime is sometimes also used as a 5th DoT effect in conjunction with Megiddo Flame. Not the most reliable but hey, I read in the fire/poison forums some people like to do that.
Explosion is never used ever again.

Here's what 3rd job should look like:
http://imgur.com/DJpu0U3

Yes, you don't use Explosion that much after 4th job, except for a couple places where it's still useful. I left mine at level 14 or something.